Telephone switch-board



(ModeL) T. W. LANE. Telephone Switch Board.

Patented June 21,1881.

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UNITED STATES PATENT OFFICE.

THOMAS WV. LANE, OF BOSTON, ASSIGNOR TO HIMSELF AND CHARLES WILLIAMS,JR, OF SOMERVILLE, MASSACHUSETTS.

TELEPHONE SWITCH-BOARD.

SPECIFICATION forming part of Letters Patent No. 243,274, dated June 21,1881.

Application filed March 18', 1881.

To all whom it may concern Be it known that I, THOMAS LANE, of Boston,in the county of Sufi'olk and State of Massachusetts, have inventedcertain Improvements in Telephone Switch-Boards, of which the followingis a specification.

This invention relates to that class of switch boards composed of aseries of parallel metal strips, each connected with a line-circuit, aseries of connecting-strips crossing the line-circuit strips at rightangles and normally disconnected or insulated from the line-circuitstrips, and movable devices, usually termed slides, on the line-circuitstrips, whereby the latter may be connected in pairs with either of theconnecting-strips.

The object of my invention is to enable a switchboard of this class tobe made in more compact form and to be more conveniently operated thanheretofore; and to this end it consists in the hereinafter-describedconstruction of the line-circuit strips and the slides thereon, wherebyeach slide is enabled to be partially rotated to make contact with oneof the connecting-strips, is prevented from being moved longitudinallyby accident when such contact is made, and is prevented from makingcontact with the connecting-strips when it is being moved longitudinallyon its line-circuit strip to transfer its contact from one connecti ng-strip to another.

The invention also consists in the arrangement of the connecting-stripsin two parallel series and interposing the line-circuit strips betweenthe two series of connecting-strips, so that they each slide by apartial rotation, and without longitudinal movement can make contactwith either of two connectingstrips, all of which I will now proceed todescribe.

Of the accompanying drawings, forming part of this specification, Figure1 represents a plan view of a switch-board embodying my invention. Fig.2 represents a section on line a: m,

,Fig. 1. Fig. 2 represents a section on line 3/ y,

Fig. 1. Figs. 3, 4, and 5 represent, respectively, an enlargedtransverse section, a top view, and a side view of one of theline-circuit strips with the slide removed. Fig. 6 rep resents atransverse section of a line-circuit strip and its slide, showing amodification in (ModeL) the construction of the former. Fig. 7represents a similar section, showing another modification. Fig. 8represents a top view of the modification shown in Fig. 7.

The same letters of reference indicate the same parts in all thefigures.

In the drawings, a represents a suitable rectangular wooden framesupporting the metallic liueeircuit strips 1) and the connecting-stripsc, the former being suitably connected to different Iinecircuits, asusual, and the latter being normally disconnected from the line-circuitstrips and arranged at right angles thereto. The connecting'strips arearranged in two parallel series, between which theline-circuit stripsare interposed, as shown in Figs. 2 and 2. Each line-circuit strip issubstantially cylindrical and provided with a longitudinal guidegroove,(1, and a series of lateral guide-grooves, e, communicating with thegroove d, and extending from both sides of the latter partly around thestrip 1).

ff represent the slides upon the line-circuit.

strips. The slides are preferably tubular, and are adapted to movelongitudinally and to retate on their strips 1). Each slide has aninwardly-proj ecting pin, h, secured to it, adapted to enter thelongitudinal groove (1, or either of the lateral grooves c of the strip1), on which it is located. \Vhen the pin h is in the longitudinalgroove (1 the slide is adapted to be moved lengthwise on the strip b,and when said pin coincides with one of the lateral grooves c the slidemay be rotated until the pin enters such groove and abuts against oneend thereof, as shown in Fig. 2. Each slide has a contact spring orarm,i, adapted to make contact with either of the connecting-strips, ashereinafter described. The spring or armi is so arranged relatively tothe pin h that when said pin is in the longitudinal groove (1 said armor spring will be separated from the connecting-strips, as shown in Fig.2, and when the pin is turned into one of the lateral grooves c said armor spring will be in contact with one of the conneetingstrips, asshownin Fig.2. The number of the lateral grooves e in each linecireuitstrip corresponds with the number in each series of connecting-strips.

It will be seen, therefore, that when the operator desires to connectany line-circuit strip with any connecting-strip the pin it of theIslideto be operatedbeingin the longitudinal groove (1 of its strip, he movesthe slide until the pin it coincides with the lateral groovecorrespondin g with the connecting-strip with which contact is to bemade, and then rotates the slide until the pin enters the lateral grooveand the arm or spring makes contactwith the connecting-strip. Whencontact is made the sides of the lateral groove prevent the slide frombeing moved longitudinally, so that the contact cannot be broken withoutfirst rotating the slide until its pin enters the groove (1. There is,therefore, no danger of the accidental break in g of the connections.\Vhen the slide is being moved longitudinally the contact arm or springdoes not touch the connecting-strips; hence there is no rattling orclicking caused by the last-named movement of the slide.

The arrangement of the connecting-strips in two series, one on eitherside of the series of line-circuit strips, enables each slide to makecontact with either of two connecting-strips by rotating it in onedirection to make contact with a strip of one series, and in theopposite direction to make contact with a strip of the other series.

By the described construction and arrangement a switch-board capable ofbeing conveniently operated and of making a large number of connectionsis produced in an exceedingly compact form.

The line circuit strips are preferably arranged horizontally, and eachslide projects through the frame a, and has upon its projecting end anoperating knob or handle, a. The line-circuit strips, when constructedas shown in Figs. 2, 3, 4, and 5, are attached to the frame a only atone end, the other end of each strip being necessarily separated fromthe frame in order that the slide may project through the frame, asshown. Each slide should be pro vided with marks or graduations toindicate the position required to enable the contact arm or spring to beturned into contact with any given connecting-strip.

If desired, the lateral grooves 0 may extend only from one side of thelongitudinal groove (1, as seen in the modification shown in Fig. 6.Inthis case the contact-arm can make contact only with theconnecting-strips of one series, and the other series ofconnecting-strips may be omitted, or every alternate line-circuit stripmay be formed to permit its slide to make contact only with theconnecting-strips of one series, the other line-circuit strips beingformed to permit their slides to make contact with the connecting-stripsof the other series.

A modification is shown in Fig. 7, in which the line-circuit strips aremade in tubular form, and provided with the longitudinal and lateralgrooves, and the slide is made in the form of a rod inclosed in thetubular strip, its contact arm or spring projecting through. the groovesin the strip. In this construction the line-circuit strip will beattached at both ends to the frame a.

Having thus described my invention, what I claim is 1. In a switch-boardof the class herein described, the combination of a series ofconnecting-strips, a series of line-circuit strips, and a series ofslides, adapted both to move longitudinally and to rotate on theline-circuit strips, substantially as and for the purposes specified.

2. In a switch-board of the class herein described, the combination oftwo series of connecting-strips, a series of line-circuit stripsinterposed between the two series of connectin gstrips, and a series ofslides, adapted both to move longitudinally and to rotate on theline-circuit strips, substantially as and for the purpose set forth.

3. In a switch -board of the class herein described, the combination ofthe line-circuit strips, the slides, and the connecting-strips, theline-circuit strips and slides being formed, substantially as described,to permit the slides to make contact with the connecting-strips by arotary movement of the slides, to prevent the slides from being movedlongitudinally while in contact with the connectingstrips, and toprevent the slides from coming in contact with the connecting-stripswhen moving longitudinally, as set forth.

4. In a switch-board of the class herein described, the combination of aseries of connecting-strips, a series of line -cireuit strips eachhaving a longitudinal guide-groove and a series of lateralguide-grooves, and a se ries of slides on said line circuit strips eachhaving a contact arm or spring, and a pin adapted to move in thelongitudinal groove, or in either of the lateral grooves of itsline-circuit strip, substantially as described.

In testimony whereof I have signed my name to this specification, in thepresence of two subscribing witnesses, this 15th day of March, A. D.1881.

THOMAS W. LANE.

Witnesses:

H. G. \VADIN, U. I BROWN.

